Focusing socket



v N. L. SNQRF FOCUSING SOCKET Filed June 5, 1922 Patented Jan. 13, 1 925.

STATES NEWTON I. SNORF, OF

HEM

[P A T CHICAGO, ILLINOIS, ASS IGNOR TO EDMULIDS& JONES CORPORA- TION, A CORPORATION OF YORK.

FOGUSING SOCKET.

To all whom it my concern:

. Be it known that I, NEWTON L. SNORF,

citizen of the United States, residin at Chicago, in the county of Cook and tate a of Illlnois, have invented certain new and useful Improvements in a Focusing Socket; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to sockets for electric lamps, and in one of its general objects aims to provide an unusually simple and inexpensive socket construction which will be particularly suitable for use under conditions in which it is necessary or desirable to adjust the-position of the socket longitudinally thereof.

In another aspect, m invention relates to the class of lamp soc ets employed with lamps of the so called Ediswan type (or lamps which have one end of the filament grounded to the metal base of the lamp).

In this aspect I aim to provide an unusually cheap and efie'ctive arrangement of the circuit connection to the socket shell, as well as an unusually simple, easily assembled and adequately insulated arrangement so of the other parts ofthe socket.

. More particularly, my invention aims to provide simple means for connecting the circuit wire to the relatively thin shell of a lamp socket without depending on a 8% thread tapped into such a thin shell. ,It

also aims to provide simple means for attaching the socket and for insulating the.

shell from this support, and desirably aims to employ the insulation used for this purto pose a so as means for resisting the thrust of a spring which normally holds the axial terminal of the socket in contact with the corresponding terminal of the lamp. Furthermore, my invention aims to provide a 5 socket of this eneral class which can easily be wired and in which both of the needed wire connections can readily be made 'di-.

rect to the socket portions which cont-act with the "lamp terminals. It also aims to provide simple means for retaining the movable body member of the socket within the socket shell while permitting this member to be withdrawn from the shell for making the circuit connection to the same. Still further and also more detailed objects will appear from the following specification and from the accompanying drawings, in which Fig. 1 is an elevation of a focusing socket embodying my invention, showing the same as holding a corresponding lamp.

Fig. 2 is a plan view of the same embodi- 'ment with the lamp detached from the same- V Fig. 3 isan enlarged central and vertical section taken through the socket of Figs. 1 and 2 along the line 33 of Fig. 2.

Fig. 4 is a horizontal section taken through the socket along the line 4-4 of Fig. 3, with the focus-adjusting portions below the socket shell omitted.

Fig. 5 is a central and vertical section taken through the body member of the socket at right angles to that of Fig. 3.

In the drawings, I am showing a socket embodying my invention and mounted on a particular type of support such as is now commonly employed in railway signal lamps, though I do not wish to be limited to its use in that particular connection. In this illustrated embodiment, the socket includes a shell 1 having a substantially cylindrical main portion equipped at its forward end with the usual bayonet slots 2 for receivin laterally'projecting ins 3 on the base 4 o a miniature Ediswan amp 5. The socket shell 1 desirably is cylindrical for its main portion and desirably has near its forward end a pair of spring fingers -6 which are bent slightly inward of the shell so as to afford a friction contact with the the metal shell 4 of the lamp base, which the mp filament.

To make the corresponding circuit con-' nection to the socket shell 1, I desirably form an ear 7 from this shell, which car extends at an acute angle, with the shell portion rearwardly thereof and is perforated for receiving a screw 8 threaded into a nut 9, the head of the screw being dislamp base shell is grounded to one end of posed on the outer side of the finger 7 so that the screw can be used for clamping the tip of a circuit wire 10 between the said finger and nut. By employing a nut somewhat wider than the finger 7 and by disposing this finger at an angle to the axis of the socket shell, I cause the nut to overlap the longitudinal edges of the aperture formed in the shell by punching out this finger, so that the resulting engagement of the nut with the walls of the perforation will prevent the nut from turning and hence will insure a firm clamping of the wire.

To support the socket shell, I mount within the rear end thereof an annular insulator 11, for which purpose I desirably enlar e the diameter of the rear end of the s ell for a distance slightly greater than the thickness of the insulator 11. I also indent into the rear face of-this insulator a plurality of fingers '12 spaced circumferentially of the shell and formed from this shell, so that the indenting of these ngers will prevent the insulator from rotatlng within the shell and W111 also hold the insulator against the shoulder at the juncture of the two differently diametered shell portions to revent the insulator from moving longitudinally of the shell. Then I slip through the bore of the insulator 11 an inwardly senting an enlarged head on the forward face of the insulator, this bushing being sufficientlyenlarged or swedged out the rear of the insulator to clamp it tightly to the latter. Thus attached, the threaded bushing 13 will form a convenient means for securing the socket shell to any threaded supporting portion, such as the threaded tube 14 of Figs. 1 and 3.

For the central terminal of the socket I provide a screw 15 extending through an axial bore in an insulating bodyv 16 which is freely slidable within the socket shell 1 and which has its axial bore enlarged for some distance from its rear end so as to receive the threaded base of a screw-eye 17 When this screw-eye is loose, the tip .of the companion circuit wire 17 can readily be inserted through the eye thereof, after which the screw 15 is tightened so as to draw the eye into the 18 of the insulating body and clamp the wire against the bight of thescrew .eye. When thus fastened, it will be evident from Fig. 3 that the wire is directly secured to the screw 15 which engages the axial lamp terminal and forms the axial terminal of the socket.

To press the last named two terminals into firm engagement, I interpose a spring 19 between the insulatin body and the perforated rear head of t e socket, in doing which I desirably reduce the diameter threaded bushing 13 preenlarged rear I bore the inner end of distance from its rear end (as shown in Fig. 3) to permit the use of a long sprlng.

I also desirably provide an insulating washer 20 adjacent to and forward of the bushing 13 so as to receive the thrust of the spring 19, and so as to prevent this spring from grounding the socket shell to the said bushing and to the support to which the bushing is connected.

With the parts thus arranged, it will be obvious that when a lamp is inserted in the socket and interlocked with the bayonet slots of the socket in the usual manner, the movable body member of the socket (consisting of the insulator 16, the screw 15 and the screw eye 17) will be moved rearwardly of the socket shell against the pressure of the spring 19. To revent. the spring from ejecting this movable body member when the lamp is detached, I desirably clamp a stop ring 21 on the insulation of the axial circuit wire 17 adjacent to the rear end of the supporting this stop ring will limit the forward movement of the body member of the socket.

For focusing purposes, the tube 14 desirably extends through a relatively large aperture 22 in a plate 23 supported by risers 24, the tube bein clamped to this plate by means of a pair 0 lock-nuts 25 and 26 which bear respectively against washers 27 and 28 disposed forwardly and rearwardly of the said plate 23. Thus arranged, the size of the aperture 22 will permit a shifting of the lfamp socket in any direction transversey o is loosened, while a shifting in position of the two lock-nuts longitudinally of the tubel t-will correspondingly shift the entire socket with respect to the supporting plate 23.

However, described a socket em dying my invention as mounted on a particular and highly desirable type of support, and have disclosed the same in an embodiment including various desirable features, I do not wish to be limited to these or other details of the construction and arrangement here disclose it being obvious that the same might be modified in many ways without departing either from the spirit of my invent-ion or from the appended claims.

I claim as my invention 1. In a lamp socket, an exteriorly threaded tube, means to support the tube, a shell, a fixed perforated insulator housed in one end of the shell, a bushing fixed to the insulator and havin interior threads engaged over and Wit the threads of the tube, an insulating washer engaged over the bushing, a contact carrier in the shell, spring means seated on the washer for tensiomng the carrier, a

tube 14,-so that its axis when either of the lock-nuts while I have illustrated and i wire extending through the tube and washextending throu h the tubular member to er and connected to the carrier, and stop be housed there y and extending beyond means on the wire engaging the opposite the opposite end of the tubular member, end of the tube to restrict movement of the andstop means on the conductor to engage 6 carrier underthe action of the spring. said opposite end'of the tubular member 2. In a lamp socket, a tubular member, thereby to restrict sliding movement of the means to support the member, a shell carcarrier outwardly of the shell. ried by one end of the member, a slidable Signed at Chicago, Illinois, May 31st, spring pressed contact carrier in the shell, 1922. 10 a conductor connected to the carrier and NEWTON Lt SNORF. 

